Bear with me, I've got a couple of 'unconnected' thoughts on this :-)
One of the aspects of WikiTree that really attracted me was the idea that it's not only about 'my' family tree, or my personal contributions. We collaborate, we build on what others before us have contributed, and (hopefully) others will find our work and carry on. Everything is a work in progress. On WikiTree, we play the long game. We think fourth-dimensionally - to paraphrase Doc Brown of Back To The Future. ;-)
To that end, I see "unconnected" as a temporary state, and not in conflict with the wider goal of connecting us all together.
I've added many unconnected files. My own family was "Unconnected" for a very long time.
Recently, I've begun adding unrelated people in anticipation of a project I'd like to get off the ground. Some of them have fascinating life stories. Some of them have no living descendants and/or no one left alive who remembers who they were. I think their stories deserve to be told. Perhaps one day, some distant relative will come around and find them, and hook them up to their own family contributions. I hope that's what happens.
Til then, playing the long game...